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Introducing NURBS modeling


show more Introducing NURBS modeling provides you with in-depth training on 3D + Animation. Taught by George Maestri as part of the Maya 2011 Essential Training show less
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Introducing NURBS modeling

Before we get started, let's go ahead and make sure we have our project set. So I'm going to go File > Project > Set, and make sure we've set this to Chap_04. Maya has two forms of modeling. As we've seen, we can use polygonal objects to create surfaces in Maya. There's also another form of modeling, and that's called NURBS modeling. And NURBS is actually an acronym. It stands for Non-uniform Rational B-Splines. And that's the last time I'll ever say that.

I have two spheres on the screen here. One's made of polygons. One's made of NURBS. The violet colored sphere is made of polygons. And as you can see, we've got all the standard stuff that we've been working with, which is vertices, edges, faces and so on. Now the one thing about a polygonal surfaces is that as you deform it, you get kind of this chunky behavior. Now we can get rid of some of this by subdividing it. But again, you really do need a fair amount of detail to get a good polygonal surface.

Now with NURBS, let's go ahead and select this, you'll notice that it has a lot less detail. The thing about a NURBS surface is that we actually have curved surfaces. It actually defines a curvature. Where here on a polygonal surface each face is actually flat, it's actually a flat plane, on a NURBS surface, it's actually a curved surface. It's defined as a curve, which is really great because you can zoom into a NURBS surface as close as you want, and it will still retain its curvature.

That's because its surface is mathematically defined. NURBS surfaces have different types of components than a polygonal surface. So if I right-click over this, you'll see, instead of faces and edges and vertices, I have what's called a Control Vertex, Isoparms, Hulls and a few others. The most important one is Control Vertex. So let's go ahead and select that. And notice how there's actually, again, less detail in the NURBS surface, but it defines a much bigger range of curvature.

So if I selected these Control Vertices, you can see that just manipulating these gives me a much more kind of rubbery, easier surface, a much more organic type of surface than a polygonal surface, which is composed of planes. Now we have a number of other types of components. Now if I take a look at the Hulls, you can kind of see how the NURBS surface is constructed. You can almost use an analogy of this is a polygonal model that's been subdivided, but there is some difference.

So don't take that analogy too far. But you can see how we have these Hulls, and around the Hulls we have kind of what we would normally call edges in the polygonal model, but in a NURBS model, it's called an Isoparm. So let's go ahead and right- click over it and select Isoparm. And then if you left-click and drag, you can just drag out any one of these Isoparm lines. These are very similar to what edge loops would do in a polygonal surface. But really, what we're just doing is defining a latitude or longitude line.

And in this particular case, these Isoparms really just determine a place where we will do some sort of action on a surface. So just really just know that they are there. So Isoparms, again, run in two directions. We have latitude and longitude types of lines. Now the other thing about NURBS surfaces is that they always are four-sided patches. So when you create a more sophisticated object, a lot of times you'll have to use multiple NURBS surfaces and tie them together in clever ways.

So actually, I'm going to go ahead and go back to Object mode here and select these spheres and delete them. And then in this file, I have a layer called Scooter. Now just go ahead and turn that on. And this is actually fully formed object made entirely out of NURBS. Now if I select on any one of these, you'll see that each part of this is actually a separate object. So what we're doing is actually we're creating objects that are kind of built out of sheets.

Each NURBS patch is, again, a four-sided patch. And then we can fold it and bend it and twist it in any sort of way to make interesting parts, like, for example, the front part of the shell of the scooter. You can see how it's almost of four-sided patch. And then the fender and wheel basically look like a four-sided patch. It's kind of revolved around. The back shell of this, you can see how it's wrapped around. And you can see also with these closed types of NURBS surfaces, you can see this darker line here is kind of where everything intersects, so it kind of wraps around.

Now as we start working with NURBS surfaces, you'll see how this actually works in practice. So this is really just an introduction to get you familiar with NURBS surfaces and how they're used to build sophisticated objects.

Introducing NURBS modeling
Video duration: 5m 3s 9h 8m Beginner

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Introducing NURBS modeling provides you with in-depth training on 3D + Animation. Taught by George Maestri as part of the Maya 2011 Essential Training

Subject:
3D + Animation
Software:
Maya
Author:
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